Beat 75 g butter with 75 g sugar until creamy. Then add the egg, flour and baking powder. Knead everything into a firm dough and distribute in a springform pan (26 cm) on the base and press up a little on the edge.
Then mix the quark with the remaining sugar, oil, egg yolks and egg and vanilla sugar. Add a little lemon juice. Finally add the milk. Spread the mass on the floor and then bake in the oven on the middle rack at approx. 200 ° C until the mass has set (you can easily test it by trying it with your finger). In the meantime, beat 2 egg whites with 3 tablespoons of sugar until stiff and spread over the solidified mass and bake for another 10 minutes. Then take it out of the oven, let it cool down and serve.